1. Field of the Invention
The present invention relates to a novel process for treating, and more particularly, purifying, water by using the technique of flocculation. More specifically, the present invention relates to a process for purifying water wherein a flocculating agent is added to the water, which addition is followed by the addition of a flocculation additive comprising a high molecular weight heteropolysaccharide.
2. Description of the Prior Art
The use of flocculating agents in the treatment of water and sludges is known, with such flocculating agents generally comprising a metallic salt such as CaCl.sub.2, FeCl.sub.2, FeCl.sub.3, FeSO.sub.4 or Fe.sub.2 (SO.sub.4).sub.3, or, a mixture of said salts. For example, see French Pat. No. 1,399,351. Aluminum sulfate is also frequently used as a water treatment flocculating agent.
Two phenomena are generally involved in flocculation, the first being the neutralization of charges, and the second being the combination of neutralized particles into coarse floccules. Aluminum sulfate and the various iron compounds, however, generally produce but the first phenomenon, thereby generating only small floccules which decant slowly. Thus, an improvement in the flocculation action of aluminum and iron comprising agents, and hence, the resulting decantation operation, is of importance for obtaining more efficient flocculation.
Regarding the treatment of water in general, one of the great difficulties thereof resides in the fact that the nature of the water to be treated is emminently variable from location to location, and even in the same location from day to day. The problem, of course, is that a particular flocculating agent or treatment process employing same may be appropriate for treatment of certain water, but may not be appropriate for the treatment of water of a different nature.
Accordingly, it is a major object of the present invention to provide a process which is generally applicable for the treatment and purification of water, regardless of the nature of the water.
Another object of the present invention is to provide a novel and effective process of purifying water employing the technique of flocculation.
Still another object of the present invention is to provide an improved process of treating water via flocculation wherein an iron or aluminum comprising flocculating agent is employed.
Other objects, features and advantages will become apparent to those skilled in the art upon a study of this disclosure and the appended claims.